EP0161684A1
Expired / Lapsed
EP
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Method of forming a carbide layer
Assignee: Toyota Central R&D Labs Inc
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Filing: 1985-05-15
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Granted: —
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Expires: 2005-05-15
Abstract
Abstract A method of forming a layer of the carbide of titanium, vanadium, etc. on the surface of an article containing carbon by employing a fluidized bed furnace. The formation of the layer is effected by disposing in the furnace a coating agent prepared from a refractory powder, a carbide forming powder composed of at least one carbide forming metal or alloy and a halid powder, and the article, and introducing a fluidizing gas into the furnace under heat to fluidize the agent. This method enables the safe and rapid formation of a carbide layer having a uniform thickness and smooth surface.
Inventors
- 👤 Tohru Arai
- 👤 Junji Endo
Bibliographic Details
Application Number
—
Jurisdiction
EP
Data Source
google_patents
Last Synchronized
2026-10-24 00:52
CPC Classifications
C; C04; C04B; C04B41/00; C04B41/009; C04B41/45; C04B41/50; C04B41/5053; C04B41/5057; C04B41/80; C04B41/81; C04B41/85; C04B41/87; C23; C23C; C23C10/00; C23C10/28; C23C10/34; C23C30/00; C23C30/005
Claims Analysis
Total Claims: 15
Claim 1
Independent Claim
109 words
A method of forming a carbide layer on the surface of an article containing carbon, which comprises the steps of: disposing in a fluidized bed furnace a coating agent comprising a refractory powder, a carbide forming powder composed of at least one carbide forming metal or alloy and a halide powder composed of at least one of a halogenated ammonium salt and a metal halide which is sublimable or vaporizable at a temperature not more than a treating temperature, and said article; and introducing a fluidizing gas into said furnace under heat to fluidize said coating agent to thereby form a carbide layer on the surface of said article.
Claim 2
Independent Claim
109 words
A method of forming a carbide layer on the surface of an article containing carbon, which comprises the steps of: disposing in a fluidized bed furnace a coating agent comprising a refractory powder, a carbide forming powder composed of at least one carbide forming metal or alloy and a halide powder composed of at least one of a halogenated ammonium salt and a metal halide which is sublimable or vaporizable at a temperature not more than a treating temperature, and said article; and introducing a fluidizing gas into said furnace under heat to fluidize said coating agent to thereby form a carbide layer on the surface of said article.
Claim 3
Dependent Claim
37 words
A method according to claim 1, wherein said coating agent contains 5 to 50% by weight of said carbide forming powder and 0.2 to 3% by weight of said halide powder, the balance being said refractory powder.
Claim 4
Dependent Claim
22 words
A method according to claim 1, wherein said refractory powder comprises at least one of alumina, silicon oxide, titanium oxide and zirconia.
Claim 5
Dependent Claim
30 words
A method according to claim 1, wherein said carbide forming metal is at least one selected from the group consisting of titanium, vanadium, niobium, tantalum, chromium, molybdenum, tungsten and manganese.
Claim 6
Dependent Claim
30 words
A method according to claim 1, wherein said halogenated ammonium salt is at least one selected from the group consisting of ammonium chloride, ammonium bromide, ammonium iodide and ammonium fluoride.
Claim 7
Dependent Claim
31 words
A method according to claim 1, wherein said metal halide is at least one selected from the group consisting of titanium fluoride, vanadium fluoride, vanadium chloride, titanium bromide and ferric chloride.
Claim 8
Dependent Claim
19 words
A method according to claim 1, wherein said coating agent has a grain size of 60 to 350 mesh.
Claim 9
Dependent Claim
21 words
A method according to claim 1, wherein said fluidizing gas is an inert gas which is nonreactive with said coating agent.
Claim 10
Dependent Claim
24 words
A method according to claim 1, wherein said fluidizing gas has a flow rate of at least 50 cm per minute in said furnace.
Claim 11
Dependent Claim
35 words
A method according to claim 1, wherein said article is formed of a material selected from the group consisting of iron, nickel, cobalt, or an alloy thereof, each containing carbon, a cemented carbide and graphite.
Claim 12
Dependent Claim
17 words
A method according to claim 1, wherein said article contains at least 0.1% by weight of carbon.
Claim 13
Dependent Claim
49 words
A method according to claim 1, wherein coarse particles of refractory powder having a grain size of 5 to 20 mesh are further disposed in said furnace between a gas inlet thereof and said coating agent, thereby preventing said gas inlet from being closed due to said coating agent.
Claim 14
Dependent Claim
46 words
13 . A method according to claim 2, wherein said coating agent has a grain size of 60 to 350 mesh, said flow rate is in the range of 50 to 700 cm per minute, and said temperature is in the range of 700°C to 1200°C.
Claim 15
Dependent Claim
12 words
A method according to claim 19, wherein said fluidizing gas is argon.
References Cited (Backward Citations)
GB1191939A
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